The Gibson 335 appears longer, but only because of the Guitars are hanging off wall hooks. Because of the different headstock shapes, the Gibson hangs slightly lower. Notice The controls and switch are in a slightly more forward on the Heritage by about 1/2 inch. The Gibson has the output jack on the front, the Heritage is on the side. I am not crazy about the Heritage 535 pickguard, so I removed it.
Both have had the standard ABR bridge replaced with Tonepros locking bridge. Both have had all
internal pots replaced with CTS 500k, and wired 50's style.
The Heritage has Lindy Fralin PAFs. and the Gibson has the original 57 Classics.
The Heritage is 3 ounces lighter than the Gibson
The Heritage neck has slightly larger frets, and is just slightly rounder.

Sonic Comparisons:

The Gibson has a bit more low frequency energy. Has a tighter more focused and compressed classic
335 type sound. Loves to be played clean, and handles overdrive well, but in a more polite kind of
way. Chords ring very clear, and notes seem to linger just a tad longer.

The Heritage is a bit looser, and sounds slightly less compressed. Notes seem to bloom and breathe just a bit more. The Fralin Hums have more upper mid freq 3D zing-ness, and vintage PAF Character.

It's rare that we see a side-by-side comparison of these two models by the same owner while they're both still in the house. Yes, it's that particular H535 and that particular ES335 but it's nice to read the positive attributes of each and that they're both keepers.